My idea is that there is another faction similar to the pirates, except they aren't spread out everywhere, they exist in a large number of neighboring systems. At some point, if there is a high amount of immigrants/defectors (http://starmadedock.net/threads/dynamic-galaxies-universe.6784/#post-96518 Check out my Dynamic Galaxies suggestion for info on immigrants/defectors) will create a sort of explosion where the ice cult will rapidly expand and cause as much damage as possible, as a sort of terrorist group. They worship Ice Crystals and any caught mining/owning them will be terminated on sight by them.